The Organic Light Emitting Diodes (OLED) display device possesses many outstanding properties of self-illumination, low driving voltage, high luminescence efficiency, short response time, high clarity and contrast, near 180° view angle, wide range of working temperature, applicability of flexible display and large scale full color display. The OLED is considered as the most potential display device.
The OLED display element is a self-emitting type display device, and generally comprises a pixel electrode and a common electrode respectively employed as being the anode and the cathode, and an organic light emitting layer positioned between the pixel electrode and the common electrode. As the proper voltages are applied to the anode and the cathode, the organic light emitting layer emits light. The organic light emitting layer comprises a Hole Injection Layer positioned on the anode, a Hole Transporting Layer positioned on the Hole Injection Layer, a light emitting layer positioned on the Hole Transporting Layer, an Electron Transport Layer positioned on the light emitting layer and an Electron Injection Layer positioned on the Electron Transport Layer. The lighting principle is that under certain voltage driving, the Electron and the Hole are respectively injected into the Electron Injection Layer and Hole Electron Injection Layer from the cathode and the anode. The Electron and the Hole respectively migrate from the Electron Transporting Layer and Hole Transporting Layer to the Emitting layer and bump into each other in the Emitting layer to form an exciton to excite the emitting molecule. The latter can illuminate after the radiative relaxation.
According to the different emissions of the lights, the OLED elements can be categorized to be the Top emission OLED and the Bottom emission OLED. The light emitted by the Top emission OLED is emitted from the top electrode. In comparison with the Bottom emission OLED which the light emitted thereby is emitted from the substrate at the bottom, the Top emission OLED has higher aperture ratio and light emitting efficiency. Because the OLED element can be easily influence by the external environments, such as water vapor and oxygen and thus the usage lifetime is shortened, there will be package structure provided outside the metal electrode of the top in general after the manufacture of the OLED element is accomplished.
The Quantumdots (QDs) light emitting material is a new technology applied in the display technology field. The Quantumdots light emitting material obeys the quantum size effect, and the properties change along with the size change of the quantum dots. As being stimulated by the light or the electricity, the quantum dots emit the colored light. The color of the light is related with the property. Thus, the emitted light can be controlled by changing the size thereof. The Quantumdots light emitting material possesses advantages of luminescence spectrum concentration and high color purity. While the Quantumdots light emitting material is employed in the display technology field, the gamut of the traditional display can be tremendously promoted to enhance the color reduction ability of the display, and it has become a popular development in the industry.